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Legit rear brake cooling

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33 replies to this topic

#1
elf_cruiser

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Hey guys, some of you know that I’ve been struggling with overheated brakes on our R35 racecar. Since moving into wheel-to-wheel racing there are two factors that are contributing to the issue. 1)Longer sessions at 30-35 minutes and 2) tight competition means having to push hard every single lap with no opportunity to give the brakes a break (dumb pun)

I have been boiling my Amsoil brake fluid during every race, mostly in the rear but also a bit in the front. And so I started thinking about some additional brake cooling a few months ago. After talking to BSE and seeing what he has done on his car and others, I came up with a game plan. I am adding 2 ducts to each rear brake, and a 3rd duct to the fronts (I already have 2 ducts on each front brake).

To start, I purchased a Stillen rear brake cooling kit from BSE, however after chatting with him the only parts that are truly useable are the ducts that attach to the undertray. The hoses and other little pieces are not rated for high temps and would most likely just melt on my car. With the Stillen ducts in hand, I started studying the rear undertrays. If you haven’t seen the Stillen kit, it’s pretty basic and the principle is that it collects air from the top of the undertrays and then funnels it into a tube where you can attach a hose. There are small NACA ducts on each side of the car that blow air onto the gas tanks. Once the air passes the gas tank it gets collected by the Stillen pieces. I decided that these small NACA ducts are not enough, so I made two large scoops that hang down off the bottom of the undertrays and will collect a huge amount of air.

On the caliper side of things, I realized that the small brake line braket would be a perfect place to weld on a small vent to direct air into the center of the rotor. I used some simple 2” exhaust couplers and smashed one side into an oval shape, then welded them to the brake line bracket at the correct angle.

My second set of ducts will capture air from the center of the undertray where there is a large NACA duct for the rear diff. I will capture that air from behind the diff and then attach hoses to the back side of the rotor, with the hoses running along the toe arms. I will be using the sway bar end link bracket to weld on another vent to focus the air into the center of the rotor.

On with the pics! Stage 1 is complete (the Stillen kit plus my scoops) and Stage 2 is underway but not done yet, so stay tuned!!
  • 7racer and choerizo like this

2010 GT-R - Matte Gray, AP/Carbotech, BSE trans cooler, BSE tune on ECUTek, H&R sways, AMSOIL, NASA-AZ TT2 and occasional DD
1976 FJ-40 Rock Buggy - tube chassis, LQ4, 700R4, NP205, Rockwells, F&R hydraulic steering, Fox, Ballistic, lots of 4130, 7068, and AR400

2001 Ford Excursion - V10, DD and occasional tow rig

facebook.com/DangerousEnterprises

Do want someday - Radical, 599 GTB w/FHP, 430 Scud, Superlite Coupe, FF Type 65 Coupe


#2
elf_cruiser

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Pics!

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  • 7racer likes this

2010 GT-R - Matte Gray, AP/Carbotech, BSE trans cooler, BSE tune on ECUTek, H&R sways, AMSOIL, NASA-AZ TT2 and occasional DD
1976 FJ-40 Rock Buggy - tube chassis, LQ4, 700R4, NP205, Rockwells, F&R hydraulic steering, Fox, Ballistic, lots of 4130, 7068, and AR400

2001 Ford Excursion - V10, DD and occasional tow rig

facebook.com/DangerousEnterprises

Do want someday - Radical, 599 GTB w/FHP, 430 Scud, Superlite Coupe, FF Type 65 Coupe


#3
thehelix112

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Nicely done man! Can't wait to hear how they go.
  • elf_cruiser likes this

#4
7racer

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Thats awesome!

Like i said on FB! Group buy! LOL make a kit!
  • elf_cruiser likes this

In7anity!!


#5
elf_cruiser

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Nicely done man! Can't wait to hear how they go.


Thanks! Me too!!
Pedal not going to the floor after 3 laps would be an improvement!

2010 GT-R - Matte Gray, AP/Carbotech, BSE trans cooler, BSE tune on ECUTek, H&R sways, AMSOIL, NASA-AZ TT2 and occasional DD
1976 FJ-40 Rock Buggy - tube chassis, LQ4, 700R4, NP205, Rockwells, F&R hydraulic steering, Fox, Ballistic, lots of 4130, 7068, and AR400

2001 Ford Excursion - V10, DD and occasional tow rig

facebook.com/DangerousEnterprises

Do want someday - Radical, 599 GTB w/FHP, 430 Scud, Superlite Coupe, FF Type 65 Coupe


#6
elf_cruiser

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Thats awesome!

Like i said on FB! Group buy! LOL make a kit!


Haha, yeah it honestly wouldn’t be too hard to make the little vents that attach to the caliper - if you really need some just let me know.

I haven’t figure out the front yet, but I will try to attach them to the knuckle so they turn with the steering. We’ll see what I can figure out in a few weeks.

Cheers!
  • 7racer and thehelix112 like this

2010 GT-R - Matte Gray, AP/Carbotech, BSE trans cooler, BSE tune on ECUTek, H&R sways, AMSOIL, NASA-AZ TT2 and occasional DD
1976 FJ-40 Rock Buggy - tube chassis, LQ4, 700R4, NP205, Rockwells, F&R hydraulic steering, Fox, Ballistic, lots of 4130, 7068, and AR400

2001 Ford Excursion - V10, DD and occasional tow rig

facebook.com/DangerousEnterprises

Do want someday - Radical, 599 GTB w/FHP, 430 Scud, Superlite Coupe, FF Type 65 Coupe


#7
thehelix112

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+1 group buy!
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#8
Aequitas & Veritas

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+3 on the group buy, I still haven't had the chance to try any ducting in the front yet. After the wedding lol


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IG - NoCrustGTR


#9
shawnhayes

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Thanks! Me too!!
Pedal not going to the floor after 3 laps would be an improvement!

 

What brake fluid are you using again?

 

Shawn

 

*Edit* - original post says Amsoil.  Have you tried Castrol SRF?  I would strongly strongly recommend you give that a go.

 

Additionally, I believe the rear caliper design from Brembo is under designed for full on race use.  Is there any rule restriction from a brake upgrade?


Edited by shawnhayes, 23 July 2018 - 07:35 AM.


#10
choerizo

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+1 count me in for the brake duct bracket (and whatever you build for the fronts)

 

Looks like this will definitely help!

 

side note: any reason you still keep the fender liners on the race car?


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#11
elf_cruiser

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What brake fluid are you using again?

Shawn

*Edit* - original post says Amsoil. Have you tried Castrol SRF? I would strongly strongly recommend you give that a go.

Additionally, I believe the rear caliper design from Brembo is under designed for full on race use. Is there any rule restriction from a brake upgrade?


Yes, I used the SRF for a couple of years before switching to Amsoil - it boiled more easily than the Amsoil. It’s been a while and it might be worth another try - but I am hopeful that all of this additional air will solve the problem entirely.

No rules against brake upgrades for NASA racing, only what my pocketbook will allow haha!!

2010 GT-R - Matte Gray, AP/Carbotech, BSE trans cooler, BSE tune on ECUTek, H&R sways, AMSOIL, NASA-AZ TT2 and occasional DD
1976 FJ-40 Rock Buggy - tube chassis, LQ4, 700R4, NP205, Rockwells, F&R hydraulic steering, Fox, Ballistic, lots of 4130, 7068, and AR400

2001 Ford Excursion - V10, DD and occasional tow rig

facebook.com/DangerousEnterprises

Do want someday - Radical, 599 GTB w/FHP, 430 Scud, Superlite Coupe, FF Type 65 Coupe


#12
elf_cruiser

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+1 count me in for the brake duct bracket (and whatever you build for the fronts)

Looks like this will definitely help!

side note: any reason you still keep the fender liners on the race car?


Fender liners - no reason other than I haven’t bothered to remove them. Maybe I will do that before we come to COTA. I do worry about rain getting into the engine bay, etc - so I will have to see what it looks like when they’re removed. We still race when it’s raining :)

If you guys are serious about getting some brake vents (ducts?) made, just PM me and we will figure it out. I may need you to send me your steel brake line brackets - I can’t find that part online. Maybe someone else can search and see if the part is available as an individual piece?

For the rear I would need the brake line bracket that bolts to the caliper and holds the brake line junction block. I would also need the sway bar end link bracket that bolts to the knuckle and connects the swaybar link.
The brake line bracket gets a 2” hose, the swaybar bracket gets a 2.5” hose.
  • 7racer and thehelix112 like this

2010 GT-R - Matte Gray, AP/Carbotech, BSE trans cooler, BSE tune on ECUTek, H&R sways, AMSOIL, NASA-AZ TT2 and occasional DD
1976 FJ-40 Rock Buggy - tube chassis, LQ4, 700R4, NP205, Rockwells, F&R hydraulic steering, Fox, Ballistic, lots of 4130, 7068, and AR400

2001 Ford Excursion - V10, DD and occasional tow rig

facebook.com/DangerousEnterprises

Do want someday - Radical, 599 GTB w/FHP, 430 Scud, Superlite Coupe, FF Type 65 Coupe


#13
shawnhayes

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Yes, I used the SRF for a couple of years before switching to Amsoil - it boiled more easily than the Amsoil. It’s been a while and it might be worth another try - but I am hopeful that all of this additional air will solve the problem entirely.

No rules against brake upgrades for NASA racing, only what my pocketbook will allow haha!!

 

Never used Amsoil, but I have to say the Castrol has been the most reliable for me, but I had front and rear brake cooling and upgraded calipers.  Maybe that actually made a difference.

 

Shawn



#14
7racer

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Yes, I used the SRF for a couple of years before switching to Amsoil - it boiled more easily than the Amsoil. It’s been a while and it might be worth another try - but I am hopeful that all of this additional air will solve the problem entirely.

No rules against brake upgrades for NASA racing, only what my pocketbook will allow haha!!


Hey Elf,

Most of the people say Castrol SRF for those with brake problems and boiling.

The pedal is pretty firm with the Amsoil? Maybe I will give that a try next time. But even at the last race shop I was in mentioned they run Castrol in their campaign car.

Speaking of which, when I was at MSR I stopped by a shop there, Doghouse? Motorsports? They are campaigning a brand new Audi R8 factory race car in the PWC series. The driver started at MSR running DEs and got noticed by the instructors as being fast and bam! Career started. They also like doing work on cars.

We started talking brake and the mechanics said he could probably get the same rotors and brakes that Nissan uses on their GTR car that they race...but since they dont race in the series anymore he said he could get it super cheap. These are the ones with like huge 2 inch thick pads!!

Elf are you interested?

In7anity!!


#15
shawnhayes

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Most of the people say Castrol SRF for those with brake problems and boiling.

The pedal is pretty firm with the Amsoil? Maybe I will give that a try next time. But even at the last race shop I was in mentioned they run Castrol in their campaign car.
 

 

7,

 

If you have no pedal problems now, don't switch unless it's a money issue.

 

The SRF is the one that most are happy with.

 

Shawn


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#16
elf_cruiser

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Never used Amsoil, but I have to say the Castrol has been the most reliable for me, but I had front and rear brake cooling and upgraded calipers. Maybe that actually made a difference.

Shawn


I’m sure the upgraded calipers would make a difference, plus the steel pistons vs aluminum.
Back when I had zero cooling here is how it went down.
Factory brake fluid done after 2 corners
Motul 600 done after 1 lap
Motul 660 done after 1 lap
Castrol SRF done after 2-3 laps
Amsoil 600 done after 2-3 laps but would come back between corners. Pedal would firm up again on the straights and be there somewhat for the next corner.

Then I started doing cooling up front and that solved the problem for DE and Time Trial sessions. Race group and full slicks has been a whole new ballgame!
  • 7racer and thehelix112 like this

2010 GT-R - Matte Gray, AP/Carbotech, BSE trans cooler, BSE tune on ECUTek, H&R sways, AMSOIL, NASA-AZ TT2 and occasional DD
1976 FJ-40 Rock Buggy - tube chassis, LQ4, 700R4, NP205, Rockwells, F&R hydraulic steering, Fox, Ballistic, lots of 4130, 7068, and AR400

2001 Ford Excursion - V10, DD and occasional tow rig

facebook.com/DangerousEnterprises

Do want someday - Radical, 599 GTB w/FHP, 430 Scud, Superlite Coupe, FF Type 65 Coupe


#17
elf_cruiser

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Hey Elf,

Most of the people say Castrol SRF for those with brake problems and boiling.

The pedal is pretty firm with the Amsoil? Maybe I will give that a try next time. But even at the last race shop I was in mentioned they run Castrol in their campaign car.

Speaking of which, when I was at MSR I stopped by a shop there, Doghouse? Motorsports? They are campaigning a brand new Audi R8 factory race car in the PWC series. The driver started at MSR running DEs and got noticed by the instructors as being fast and bam! Career started. They also like doing work on cars.

We started talking brake and the mechanics said he could probably get the same rotors and brakes that Nissan uses on their GTR car that they race...but since they dont race in the series anymore he said he could get it super cheap. These are the ones with like huge 2 inch thick pads!!

Elf are you interested?


Wow! What a lucky guy to get picked up by a pro team! I’m glad stories like that are still out there.

As for the brakes I would like to upgrade eventually but they are pretty far down on the list. I’ve had some financial setbacks this year (rental properties, ugh) and wasn’t able to do any of the upgrades I had planned so far. There is always next year!!

Cheers 7,
  • 7racer and thehelix112 like this

2010 GT-R - Matte Gray, AP/Carbotech, BSE trans cooler, BSE tune on ECUTek, H&R sways, AMSOIL, NASA-AZ TT2 and occasional DD
1976 FJ-40 Rock Buggy - tube chassis, LQ4, 700R4, NP205, Rockwells, F&R hydraulic steering, Fox, Ballistic, lots of 4130, 7068, and AR400

2001 Ford Excursion - V10, DD and occasional tow rig

facebook.com/DangerousEnterprises

Do want someday - Radical, 599 GTB w/FHP, 430 Scud, Superlite Coupe, FF Type 65 Coupe


#18
gtrguyinaz

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The ducting looks great. I hope it makes a difference. Send me a text and tell me when you are going to COTA.


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#19
elf_cruiser

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Alright guys, Stage 2 for rear brake cooling is complete now as well. This was a really weird one, I looked at several possibilities before deciding on this design. I really, really wanted to avoid hacking up the rear diffuser and ruining the airflow underneath it. So, I looked and looked and finally realized that there was a way to get some air flow from behind the rear diff. As most of you know, the stock GT-R has a NACA duct under the rear diff that blows air across the bottom of the diff. Nissan also placed a scoop on the topside of the diffuser to channel some air up the back of the rear diff. Then there are two large openings in the subframe that all that air to exit the diff area and flow out the back of the car. I realized that I could make a pair of small scoops to fit those openings and redirect that air towards the brakes. I don’t expect this to bring as much airflow as the Stillen ducts, but every but will help. I tested with a shop fan and there is some decent airflow through these new ducts!
So now I have a total of 4 brake ducts for the rear of the car. 2 on each side, one for the caliper and one for the opposite side of the rotor, using the swaybar end link bracket on the knuckle. F$ck you, hot brakes!!
  • 7racer likes this

2010 GT-R - Matte Gray, AP/Carbotech, BSE trans cooler, BSE tune on ECUTek, H&R sways, AMSOIL, NASA-AZ TT2 and occasional DD
1976 FJ-40 Rock Buggy - tube chassis, LQ4, 700R4, NP205, Rockwells, F&R hydraulic steering, Fox, Ballistic, lots of 4130, 7068, and AR400

2001 Ford Excursion - V10, DD and occasional tow rig

facebook.com/DangerousEnterprises

Do want someday - Radical, 599 GTB w/FHP, 430 Scud, Superlite Coupe, FF Type 65 Coupe


#20
elf_cruiser

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Pics!

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  • 7racer and thehelix112 like this

2010 GT-R - Matte Gray, AP/Carbotech, BSE trans cooler, BSE tune on ECUTek, H&R sways, AMSOIL, NASA-AZ TT2 and occasional DD
1976 FJ-40 Rock Buggy - tube chassis, LQ4, 700R4, NP205, Rockwells, F&R hydraulic steering, Fox, Ballistic, lots of 4130, 7068, and AR400

2001 Ford Excursion - V10, DD and occasional tow rig

facebook.com/DangerousEnterprises

Do want someday - Radical, 599 GTB w/FHP, 430 Scud, Superlite Coupe, FF Type 65 Coupe





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